Researchers continuously pursue a better understanding of the physiological behaviors of living cells and tissues in order to further advance the frontiers of bioscience and biotechnology. The physiological behaviors and responses of wide-type and genetically modified cells and tissues are currently tested using cell-based assays. For example, during large-scale drug screening in the pharmaceutical industry, in vitro cultured cells for the cell-based assays are used to characterize certain properties, such as potency and toxicity, of chemical compounds for potential new drugs. The cell-based assays are also used, for example, in determining patient-specific treatments in personalized medicine, fast pathogen screening for epidemic disease detections, and detecting biohazards and pollutants in environmental monitoring.
However, cells are highly complex systems with numerous molecules operating in hundreds of pathways to maintain their proper functions, phenotypes, and physiological behaviors. With such a high level of complexity, the cells often undergo concurrent multiple physical responses when subjected to external biochemical stimuli or physiological condition shifts. Accurate characterization of these changes is difficult using conventional sensing technology.